Automatic door closer

ABSTRACT

An automatic door closer wherein the spring which urges the door closing spindle to its starting position bears against the piston of the braking device for the spindle and against a retainer which is adjustable by means of a shaft extending from the housing of the door closer. In this way, the initial stress upon the spring can be changed in fully assembled and installed condition of the door closer. The cylinder of the braking device is rigid with the housing and has an end wall which faces the spindle and is traversed by the piston rod of the piston. The end wall serves as a support for a check valve which admits fluid into the compartment between such end wall and the piston when the spindle rotates during opening of the door but prevents the flow of fluid when the spindle rotates toward its starting position.

[451 Apr. 3, 1973 FOREIGN PATENTS OR APPLICATIONS 554,983 7/1943 England...............................188/322 Primary Examiner-Francis K. Zugel Assistant ExaminerPeter A. Aschenbrenner AttorneyMichae1 S. Striker [57] ABSTRACT An automatic door closer wherein the spring which urges the door closing spindle to its starting position bears against the piston of the braking device for the spindle and against a retainer which is adjustable by means of a shaft extending from the housing of the door closer. In this way, the initial stress upon the spring can be changed in fully assembled and installed condition of the door closer. The cylinder of the braking device is rigid with the housing and has an end wall which faces the spindle and is traversed by the piston rod of the piston. The end wall serves as a support for a check valve which admits fluid into the compartment between such end wall and the piston when the spindle rotates during opening of the door but prevents the flow of fluid when the spindle rotates toward its starting position.

Data

Sept. 30, 1969 Germany.....................P 19 49 240.1

Ellis et al.... Rosentreter Bommer.....

in dt m mos fi u 3km KRS 6 Horst Tillma Ennepetal-Voerde, Germany [73] Assignee: Dorken & Mankel KG, Ennepetal- Voerde, Germany Sept. 22, 1970 Foreign Application Priority References Cited UNITED STATES PATENTS United States Patent 91 Tillmann [54] AUTOMATIC DOOR CLOSER [75] Inventor:

22 Filed:

21 App1.No.:74,352'

[52] US. Cl. [51] Int. [58] Field ofSearch.....................

5 Claims, 2 Drawing Figures 8/1930 Garrison..... 441,274 11/1890 Bardsley.....

AUTOMATIC noon CLOSER BACKGROUND OF THE INVENTION moved toward an open position and under the action of 1 the energy storing means when the door panel is free to move toward its closed position.

Automatic door closers of the just outlined character are further provided with breaking means which prevents the closing of the door panel at an excessive speed. Such braking means normally comprises a cylinder and piston assembly which displaces a hydraulic working medium. When the door panel moves toward its closed position, the fluid medium is caused to flow through one or more flow restrictors which determine the speed of closing movement. In order to change the speed of closing movement of the door panel, it is desirable to provide the door closer with means for adjusting the initial stress upon the energy storing means which normally comprises one or more strong helical springs or the like. As a rule, the adjusting means comprises a spring retainer which is movable between several positions each corresponding to a different initial stress upon the energy storing means. However, such adjusting means cannot be mounted in all presently known types of door closers. Furthermore, the adjusting means which are presently used in door closers are normally designed and mounted in such a way that they can be reached only upon partial or substantial dismantling of the door closer, particularly in response to at least partial opening of the housing wherein the spindle for the door panel rotates and which contains the aforementioned cylinder and piston assembly.

It is further known to assemble a door closer in such a way that the energy storing means is fully independent of the braking means. For example, it was proposed to mount the spring or springs of the energy storing means at the one side and the braking means at the other side of the spindle. Such door closers are bulky and more complicated than those wherein the energy storing means cooperates directly with the braking means or wherein the energy storing means and the braking means are mounted at the same side of the spindle.

SUMMARY OF THE INVENTION An object of the invention is to provide an automatic door closer wherein the energy storing means is readily adjustable and wherein access to the adjusting means for the energy storing means can be gained without necessitating even partial dismantling of the door,

means can be changed by unskilled persons and wherein such adjustment can be carried out without necessitating the use of special tools.

An additional object of the invention is to provide a novel and improved adjusting mechanism or the energy storing means of automatic door closers.

Still another object of the invention is to provide an adjusting mechanism which can be used with equal advantage in door closers wherein the door panel is movable to a single open position or in door closers wherein the door panel can move to an open position by turning in either direction from its closed or sealing position.

The invention is embodied in an automatic door closer comprising a preferably elongated housing which is at least substantially filled with a hydraulic fluid, a spindle rotatably mounted in the housing and having a portion which is connectable to a door panel so as to be rotated by or to rotate the door panel, prestressed energy storing means preferably including one or more strong helical springs installed in the housing and arranged to store additional energy in response to rotation of the spindle from a starting or idle position in which the door panel is closed and to urge the spindle toward such idle position when the door panel is permitted to move back toward its closed position, and braking means installed in the housing to control the speed of rotation of the spindle, at least while the spindle rotates toward its idle position. The braking means comprises a cylinder member, a piston member which is received in the cylinder member, and a piston rod connected to the piston member. One of these members is rigid with the housing and the other member is operatively connected with the spindle for axial movement with reference to the one member in response to rotation of the spindle. The cylinder member has a wall which is traversed by the piston rod and is located at that end of the cylinder member which is nearer to the spindle. This renders it possible to mount the spring of the energy storing means between the other member of the braking means and that end wall of the housing which is remote from the spindle. The spring can urge the spindle toward the idle position by way of the other member of the braking means. The housing further accommodates an adjustable retainer for the spring; this retainer is mounted in the housing adjacent to the end wall and can be moved axially of the spring to change the initial stress by means of a shaft which meshes with the retainer and has an input portion extending outwardly through the end wall so that it can be engaged by a wrench or the like without necessitating even partial dismantling of the door closer.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved door closer itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG.'1 is a longitudinal vertical sectional view of a door closer which embodies the invention, the section being taken in the direction of arrows as seen from the line II of FIG. 2; and

FIG. 2 is a horizontal section view substantially as seen in the direction of arrows from the line llll of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The automatic door closer of FIGS. 1 and 2 comprises an elongated housing which can be installed in a suitable recess of the floor below the lower edge face of a door panel, not shown. The top wall or cover 10a of the housing 10 is provided with a tapped bore which receives a ring-shaped sealing member 11 surrounding a portion of a vertical closer drive spindle 13. The sealing member 11 is to be removed when a workman desires to gain access to certain parts in the adjacent portion of the housing 10. The upper end portion of the spindle 13 extends beyond the housing 10 and is connected to the door panel in a conventional way not forming part of the present invention. That end wall of the housing 10 which is remote from the sealing member 11 constitutes an externally threaded and readily removable annular closure or plug 12.

The spindle 13 is rotatable in an upper antifriction bearing 13a which is installed in the sealing member 11 and a lower antifriction bearing 13b which is mounted in the bottom wall 10b of the housing 10. The sealing member 11 further accommodates one or more packings 11a which prevent leakage of a hydraulic working medium from the interior of the housing 10. A median portion of the spindle 13 is provided with or is rigidly connected to a substantially heart-shaped cam 14 which is disposed at a level between the bearings 13a, 13b and whose peripheral surface is tracked by two discrete roller followers 18, 18a located diametrically opposite each other with reference to the axis of the spindle 13. The cam 14 is flanked by two plates 15 which are provided with elongated slots 16 for the median portion of the spindle 13. These plates constitute a carriage which rotatably supports the roller followers 18, 18a and is reciprocable in the housing 10 in response to rotation of the spindle 13. The roller followers 18, 18a are mounted on vertical shafts 17 whose ends are journalled in the respective plates. The carriage is connected to a crosshead 19 by means of screws 21 or analogous fasteners, and the cross-head 19 is rigid with or forms part of an elongated piston rod which forms part of the braking means for the spindle 13. The piston rod 20 extends with clearance through the central opening of a ring-shaped element 23 which is sealingly received in the housing 10 and constitutes one end wall of a cylinder 22 which, in the illustrated embodiment, forms an integral (median) part of the housing 10. The right-hand end portion of the piston rod 20 is articulately coupled to a piston 25 by means of a cross pin 23 in such a way that the piston rod has limited freedom of angular movement about the axis of the pin 24. The housing 10 further contains a strong energy storing helical spring 26 which serves to bias the piston 25 in a direction to the left, as viewed in the drawing, so that the roller follower 18 of the carriage (plates 15) normally bears against the peripheral surface of the cam 14. The piston 25 has a smallerdiameter centering extension 27 which extends into the adjacent end convolutions of the spring 26. The extension 27 further accommodates a safety valve or pressure relief valve 28 which can open automatically when the fluid pressure in a compartment 38 between the wall 23 and piston 25 rises to a predetermined maximum permissible value; the valve 28 then permits pressurized fluid to flow from the compartment 38 into a space 41 for the spindle 13 and cam 14.

The right-hand end convolution of the spring 26 reacts against an adjustable retainer here shown as a nut 29 which meshes with an externally threaded adjusting shaft 32 and has a radial projection 30 extending into an internal groove 31 machined into the cover 10a of the housing 10. The projection 30 and groove 31 serve as a means for holding the retainer 29 against rotation but the latter is free to move axially (and to thus change the initial stress upon the spring 26) in response to rotation of the shaft 32. This shaft extends through the plug 12 of the housing 10 and is provided with an input portion or head 33 which is of other than circular outline and is accessible at the outer side of the plug 12 so that the bias of the spring 26 can be changed by rotating the head 33 by means of a suitable tool without necessitating removal of the housing 10 from the floor and/or detachment of the spindle 13 from the door panel. The shaft 32 has a flange 32a which bears against the inner side of the plug 12 so that the shaft is held against axial movement in a direction to the right, as viewed in the drawing. The bias of the spring 26 is strong enough to hold the shaft 32 against axial move ment in a direction toward the spindle 13.

The annular wall or ring 23 normally abuts against an internal shoulder 10c of the housing 10 under the action of a ring-shaped spring 34. The wall 23 supports an annular confining ring 35 having inwardly extending elastic tongues which can engage an annular flange ofa sealing ring 37. The entraining ring 35 is installed in a recess 36 of the wall 23. The ring 37 is in sealing engagement with the peripheral surface of the piston rod 20.

The door closer is further provided with suitable channel means (not shown) which connects the space 41 for the cam 14 with the chamber for the spring 26. The compartment 38 is of annular shape because it is traversed by the piston rod 20 and is connected with the aforementioned channel means by way of a passage 39a containing an adjustable flow restrictor 39 The housing 10 has a window 40 which is normally sealed by a plug or the like but can be exposed to permit insertion or removal of the cross pin 24. The window 40 is provided in the top wall 10a of the housing 10. The entire housing 10 is filled with the aforementioned hydraulic working fluid, preferably oil. The operation:

In the starting or idle position of the spindle 13 as shown in FIGS. 1 and 2, the door panel is held in the closed position. Such door panel can be moved to an open position while the spindle 13 rotates in a clockwise or in a counterclockwise direction. It is assumed that the door panel ispushed or pulled in a direction to rotate the spindle 13 clockwise, as viewed in FIG. 2. The cam 14 shares such angular movement of the spindle l3 and shifts the carriage (plates 15) in a direction to the right, as viewed in the drawing, through the intermediary of the right-hand roller follower 18. The carriage displaces the piston rod 20 and the piston 25 so that the latter moves toward' the plug 12 and causes the spring 26 to store additional energy. As the piston rod 20 moves in a direction to the right, the flange of the sealing element 37 in the recess 36 of the wall 23 moves away from the adjacent internal surface of the wall 23 so that the fluid is free to flow from the space 41, around the flange of the sealing element 37, and into the compartment 38.

If the door panel is thereupon released, it automatically returns to its closed position under the action of the spring 26 which is free to dissipate energy and pushes the piston 25 in a direction to the left, as viewed in the drawing, so that the roller follower 18 causes the cam 14 and the spindle 13 to turn in a counterclockwise direction. The speed of such return movement of the door panel to its closed position is determined by the flow restrictor 39 in the passage 39a which constitutes the only available outlet for the expulsion of fluid from the compartment 38. This is due to the fact that, when the piston rod 20 moves in a direction to the left, i.e., when the spring 26 is free to dissipate additional energy which was stored therein during opening of the door, the flange of the sealing element 37 moves from the inwardly extending tongues of the ring 35 into sealing engagement with the internal surface of the wall 23 to thus seal the path for direct flow of fluid between the compartment 38 and the space 41.

If the door panel is moved toward its closed position in response to the application of an external force which is strong enough to overcome the action of the spring in the relief valve 28, the latter opens in automatic response to a rise in fluid pressure in the compartment 38 to a predetermined maximum permissible value and allows the fluid to escape into the aforementioned channel means which connects the chamber for the spring 26 with the space 41. Thus, the valve 28 constitutes a safety device which prevents damage to the parts of the door closer when the door panel is forcibly moved to its closed position at a speed exceeding that which is determined by the flow restrictor 39. Moreover, when the door panel is forcibly moved toward its closed position, the peripheral surface of the cam 14 engages the left-hand roller follower 18a which thereupon cooperates with the cam to resist the movement of the door panel at an excessive speed.

An important advantage of the just described door closer is that the input portion or head 33 of the adjusting shaft 32 is accessible at all times. Thus, the operator merely moves the door panel to an open or partly open position so that the cover a of the housing 10 is exposed, and the head 33 is then ready to be engaged and rotated by a wrench or another suitable tool to change the initial stress upon the spring 26. As mentioned above, the adjustment of the bias of the door closing spring in conventional door closers necessitates at least partial opening of the housing.

The sealing element 37 constitutes the valve member of a check valve or one-way valve which permits the fluid to flow from the space 41 into the compartment 38 but seals the compartment from such space when the piston 25 is caused to move in a direction to expel the fluid from the compartment 38.

The placing of the adjusting shaft 32 into that portion of the housing 10 which is remotest from the spindle 13 is made possible due to the provision of the member 23 which constitutes one end wall of the cylinder 22 and is located between the cylinder and the spindle. This leaves ample room for mounting of the spring 26 in the area between the plug 12 and the piston 25 so that the head 33 of the adjusting shaft 32 can extend beyond the housing 10 and is readily accessible to allow for adjustment of the initial stress upon the spring.

It is clear that the improved door closer is susceptible of many additional modifications without departing from the spirit of the present invention. For example, the piston 25 can be fixedly mounted in the housing 10 if the housing accommodates a discrete cylinder which surrounds the piston and is coupled to the carriage by arms or the like for movement in response to rotation of the spindle 13. Moreover, the spring 26 need not be mounted to bear directly against the piston or cylinder of the braking means in the housing 10; it is equally possible to provide in the housing a separate stressing member which receives motion directly from the carriage (plates 15) or from the cam 14 and serves to stress the spring 26 when the door panel is being moved toward its open position. Also, the piston 25 can be rigidly secured to or made integral with the piston rod 20. The connection by means of a cross pin 24 or the like is preferred because the parts of the braking means (including the cylinder 22, piston 25 and piston rod 20) need not be machined with utmost precision if the piston rod has limited freedom of movement with reference to the piston.

Without further analysis,'the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features which fairly constitute essential characteristics of the generic and specific aspects of my contribution to the art and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended 1. In an automatic door closer, a combination comprising a closed housing filled at least substantially with a hydraulic fluid; a spindle rotatably mounted in said housing and having a portion connectable to a door panel; prestressed energy storing means provided in said housing and arranged to store additional energy in response to rotation of said spindle from an idle position corresponding to the closed position of said door panel, and to urge said spindle towards such idle position when the door panel is permitted to move towards its closed position; braking means installed in said housing to control the speed of rotation of the spindle, at least during movement to said idle position, and comprising a cylinder member, a piston member in said cylinder member and a piston rod connected with said piston member, one of said members being operatively connected with said spindle for axial movement relative to the other member in response to rotation of said spindle, said cylinder member having a wall located at that end of said cylinder member which is nearer to said spindle, said wall being formed with an opening through which said piston rod extends with clearance, said wall and said piston member defining a compartment at one side of said wall through which said piston rod extends, and adjustable flow restrictor means providing communication between said compartment and the interior of said closed housing on the other side of said wall; and one-way valve means comprising a ring-shaped valve member sealingly surrounding said piston rod, said valve member being moved into sealing engagement with said wall during movement of said one member in a direction towards said wall so that fluid from said compartment can flow into the interior of said housing at the other side of said wall only through said flow restrictor means, and permitting the fluid to enter said compartment through said clearance and past said valve member during movement of said one member in the opposite direction.

2. A combination as defined in claim 1, wherein said energy storing means comprises a helical spring bearing against said piston member, said piston member having an extension of reduced diameter surrounded by an end portion of said spring, and further comprising safety valve means in said extension to permit escape of fluid from said compartment when the fluid pressure therein reaches a predetermined maximum value.

3. A combination as defined in claim 1, wherein said energy storing means comprises spring means which is at least substantially coaxial said piston member.

4. A combination as defined in claim 1, wherein said energy storing means is arranged to bias said spindle toward said idle position by way of said one member of said braking means and further comprising adjustable retainer means for said energy storing means, said housing having an end wall remote from said spindle and said retainer means being located between said end wall and said one member of said braking means.

5. A combination as defined in claim 1, wherein said one member is said piston member and said piston rod is arranged to transmit motion to said piston member in response to rotation of said spindle from said idle position, said cylinder member being rigid with said housing. 

1. In an automatic door closer, a combination comprising a closed housing filled at least substantially with a hydraulic fluid; a spindle rotatably mounted in said housing and having a portion connectable to a door panel; prestressed energy storing means provided in said housing and arranged to store additional energy in response to rotation of said spindle from an idle position corresponding to the closed position of said door panel, and to urge said spindle towards such idle position when the door panel is permitted to move towards its closed position; braking means installed in said housing to control the speed of rotation of the spindle, at least during movement to said idle position, and comprising a cylinder member, a piston member in said cylinder member and a piston rod connected with said piston member, one of said members being operatively connected with said spindle for axial movement relative to the other member in response to rotation of said spindle, said cylinder member having a wall located at that end of said cylinder member which is nearer to said spindle, said wall being formed with an opening through which said piston rod extends with clearance, said wall and said piston member defining a compartment at one side of said wall through which said piston rod extends, and adjustable flow restrictor means providing communication between said compartment and the interior of said closed housing on the other side of said wall; and one-way valve means comprising a ring-shaped valve member sealingly surrounding said piston rod, said valve member being moved into sealing engagement with said wall during movement of said one member in a direction towards said wall so that fluid from said compartment can flow into the interior of said housing at the other side of said wall only through said flow restrictor means, and permitting the fluid to enter said compartment through said clearance and past said valve member during movement of said one member in the opposite direction.
 2. A combination as defined in claim 1, wherein said energy storing means comprises a helical spring bearing against said piston member, said piston member having an extension of reduced diameter surrounded by an end portion of said spring, and further comprising safety valve means in said extension to permit escape of fluid from said compartment when the fluid pressure therein reaches a predetermined maximum value.
 3. A combination as defined in claim 1, wherein said energy storing means comprises spring means which is at least substantially coaxial said piston member.
 4. A combination as defined in claim 1, wherein said energy storing means is arranged to bias said spindle toward said idle position by way of said one member of said braking means and further comprising adjustable retainer means for said energy storing means, said housing having an end wall remote from said spindle and said retainer means being located between said end wall and said one member of said braking means.
 5. A combination as defined in claim 1, wherein said one member is said piston member and said piston rod is arranged to transmit motion to said piston member in response to rotation of said spindle from said idle position, said cylinder member being rigid with said housing. 